1 /*
2 * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "asm/macroAssembler.inline.hpp"
27 #include "code/compiledIC.hpp"
28 #include "code/icBuffer.hpp"
29 #include "code/nmethod.hpp"
30 #include "memory/resourceArea.hpp"
31 #include "runtime/mutexLocker.hpp"
32 #include "runtime/safepoint.hpp"
33 #ifdef COMPILER2
34 #include "opto/matcher.hpp"
35 #endif
36
37 // Release the CompiledICHolder* associated with this call site is there is one.
38 void CompiledIC::cleanup_call_site(virtual_call_Relocation* call_site) {
39 // This call site might have become stale so inspect it carefully.
40 NativeCall* call = nativeCall_at(call_site->addr());
41 if (is_icholder_entry(call->destination())) {
42 NativeMovConstReg* value = nativeMovConstReg_at(call_site->cached_value());
43 InlineCacheBuffer::queue_for_release((CompiledICHolder*)value->data());
44 }
45 }
46
47 bool CompiledIC::is_icholder_call_site(virtual_call_Relocation* call_site) {
48 // This call site might have become stale so inspect it carefully.
49 NativeCall* call = nativeCall_at(call_site->addr());
50 return is_icholder_entry(call->destination());
51 }
52
53 // ----------------------------------------------------------------------------
54
55 // A PPC CompiledStaticCall looks like this:
56 //
57 // >>>> consts
58 //
59 // [call target1]
60 // [IC cache]
61 // [call target2]
62 //
63 // <<<< consts
64 // >>>> insts
65 //
66 // bl offset16 -+ -+ ??? // How many bits available?
67 // | |
68 // <<<< insts | |
69 // >>>> stubs | |
70 // | |- trampoline_stub_Reloc
71 // trampoline stub: | <-+
72 // r2 = toc |
73 // r2 = [r2 + offset] | // Load call target1 from const section
74 // mtctr r2 |
75 // bctr |- static_stub_Reloc
76 // comp_to_interp_stub: <---+
77 // r1 = toc
78 // ICreg = [r1 + IC_offset] // Load IC from const section
79 // r1 = [r1 + offset] // Load call target2 from const section
80 // mtctr r1
81 // bctr
82 //
83 // <<<< stubs
84 //
85 // The call instruction in the code either
86 // - branches directly to a compiled method if offset encodable in instruction
87 // - branches to the trampoline stub if offset to compiled method not encodable
88 // - branches to the compiled_to_interp stub if target interpreted
89 //
90 // Further there are three relocations from the loads to the constants in
91 // the constant section.
92 //
93 // Usage of r1 and r2 in the stubs allows to distinguish them.
94
95 const int IC_pos_in_java_to_interp_stub = 8;
96 #define __ _masm.
97 void CompiledStaticCall::emit_to_interp_stub(CodeBuffer &cbuf) {
98 #ifdef COMPILER2
99 // Get the mark within main instrs section which is set to the address of the call.
100 address call_addr = cbuf.insts_mark();
101
102 // Note that the code buffer's insts_mark is always relative to insts.
103 // That's why we must use the macroassembler to generate a stub.
104 MacroAssembler _masm(&cbuf);
105
106 // Start the stub.
107 address stub = __ start_a_stub(CompiledStaticCall::to_interp_stub_size());
108 if (stub == NULL) {
109 Compile::current()->env()->record_out_of_memory_failure();
110 return;
111 }
112
113 // For java_to_interp stubs we use R11_scratch1 as scratch register
114 // and in call trampoline stubs we use R12_scratch2. This way we
115 // can distinguish them (see is_NativeCallTrampolineStub_at()).
116 Register reg_scratch = R11_scratch1;
117
118 // Create a static stub relocation which relates this stub
119 // with the call instruction at insts_call_instruction_offset in the
120 // instructions code-section.
121 __ relocate(static_stub_Relocation::spec(call_addr));
122 const int stub_start_offset = __ offset();
123
124 // Now, create the stub's code:
125 // - load the TOC
126 // - load the inline cache oop from the constant pool
127 // - load the call target from the constant pool
128 // - call
129 __ calculate_address_from_global_toc(reg_scratch, __ method_toc());
130 AddressLiteral ic = __ allocate_metadata_address((Metadata *)NULL);
131 __ load_const_from_method_toc(as_Register(Matcher::inline_cache_reg_encode()), ic, reg_scratch);
132
133 if (ReoptimizeCallSequences) {
134 __ b64_patchable((address)-1, relocInfo::none);
135 } else {
136 AddressLiteral a((address)-1);
137 __ load_const_from_method_toc(reg_scratch, a, reg_scratch);
138 __ mtctr(reg_scratch);
139 __ bctr();
140 }
141
142 // FIXME: Assert that the stub can be identified and patched.
143
144 // Java_to_interp_stub_size should be good.
145 assert((__ offset() - stub_start_offset) <= CompiledStaticCall::to_interp_stub_size(),
146 "should be good size");
147 assert(!is_NativeCallTrampolineStub_at(__ addr_at(stub_start_offset)),
148 "must not confuse java_to_interp with trampoline stubs");
149
150 // End the stub.
151 __ end_a_stub();
152 #else
153 ShouldNotReachHere();
154 #endif
155 }
156 #undef __
157
158 // Size of java_to_interp stub, this doesn't need to be accurate but it must
159 // be larger or equal to the real size of the stub.
160 // Used for optimization in Compile::Shorten_branches.
161 int CompiledStaticCall::to_interp_stub_size() {
162 return 12 * BytesPerInstWord;
163 }
164
165 // Relocation entries for call stub, compiled java to interpreter.
166 // Used for optimization in Compile::Shorten_branches.
167 int CompiledStaticCall::reloc_to_interp_stub() {
168 return 5;
169 }
170
171 void CompiledStaticCall::set_to_interpreted(methodHandle callee, address entry) {
172 address stub = find_stub();
173 guarantee(stub != NULL, "stub not found");
174
175 if (TraceICs) {
176 ResourceMark rm;
177 tty->print_cr("CompiledStaticCall@" INTPTR_FORMAT ": set_to_interpreted %s",
178 p2i(instruction_address()),
179 callee->name_and_sig_as_C_string());
180 }
181
182 // Creation also verifies the object.
183 NativeMovConstReg* method_holder = nativeMovConstReg_at(stub + IC_pos_in_java_to_interp_stub);
184 NativeJump* jump = nativeJump_at(method_holder->next_instruction_address());
185
186 assert(method_holder->data() == 0 || method_holder->data() == (intptr_t)callee(),
187 "a) MT-unsafe modification of inline cache");
188 assert(jump->jump_destination() == (address)-1 || jump->jump_destination() == entry,
189 "b) MT-unsafe modification of inline cache");
190
191 // Update stub.
192 method_holder->set_data((intptr_t)callee());
193 jump->set_jump_destination(entry);
194
195 // Update jump to call.
196 set_destination_mt_safe(stub);
197 }
198
199 void CompiledStaticCall::set_stub_to_clean(static_stub_Relocation* static_stub) {
200 assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "mt unsafe call");
201 // Reset stub.
202 address stub = static_stub->addr();
203 assert(stub != NULL, "stub not found");
204 // Creation also verifies the object.
205 NativeMovConstReg* method_holder = nativeMovConstReg_at(stub + IC_pos_in_java_to_interp_stub);
206 NativeJump* jump = nativeJump_at(method_holder->next_instruction_address());
207 method_holder->set_data(0);
208 jump->set_jump_destination((address)-1);
209 }
210
211 //-----------------------------------------------------------------------------
212 // Non-product mode code
213 #ifndef PRODUCT
214
215 void CompiledStaticCall::verify() {
216 // Verify call.
217 NativeCall::verify();
218 if (os::is_MP()) {
219 verify_alignment();
220 }
221
222 // Verify stub.
223 address stub = find_stub();
224 assert(stub != NULL, "no stub found for static call");
225 // Creation also verifies the object.
226 NativeMovConstReg* method_holder = nativeMovConstReg_at(stub + IC_pos_in_java_to_interp_stub);
227 NativeJump* jump = nativeJump_at(method_holder->next_instruction_address());
228
229 // Verify state.
230 assert(is_clean() || is_call_to_compiled() || is_call_to_interpreted(), "sanity check");
231 }
232
233 #endif // !PRODUCT